Earthquake Hazards and Safety

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Vocabulary

liquefaction- when an earthquake is too strong,the trembling breaks out turning dirt into muck
aftershock- sometimes a significantly smaller quake that takes place after the main quake happens
tsunamis- when a strong earthquake occurs by some body of water, the water gets thrown onto the land creating huge waves
base-isolated-buildings- a building made to withstand the earthquake's enormous power

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Outline

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How Earthquakes Cause Damage

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• Shaking of Earthquakes cause damage
  • S waves more side to side motion, causing damage
  • causes avalanches or landslides
    • in coastal regions tsunamis cause most damage
• Local Soil Conditions
  • houses on hard dense rock shake less
  • houses on thick soil shake more
• Liquefaction
  • turns loose soil into liquid mud
    • makes cracks in ground like the earthquake in Anchorage, Alaska
  • Liquefaction happens in soil that is moist
    • makes buildings sink
    • makes land slides
• Aftershocks
  • earthquake that happens after the first earthquake
    • can happen hours, days, or months later
• Tsunamis
  • happens when earthquakes happen underwater and make a wave
    • starts at the epicenter goes across the ocean
    • creates multiple waves that are wide spread between 100-200 kilometers
    • height of the waves is low but becomes bigger (as big as a 6 story building)

Making Building Safer

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• people die in earthquakes from collapsing buildings
  • building must be made safer and stronger
• Choice of Location
  • steep hills are exposed to landslides
  • filled land shakes hard
  • unsafe on fault
    • earthquake is strongest there
    • farther away from the fault the weaker the earthquake
• Construction Methods
  • houses must be strong to beat earthquakes
    • to avoid liquefaction, soft ground built homes are anchored to rock bellow some with highways
  • re-enforced buildings are called base-isolated buildings
    • building rests on pads and springs in a base isolated building

Protecting Yourself During an Earthquake

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• Main danger in an earthquake: falling glass and objects
  • best way to protect yourself is to duck, cover, and hold
    • under a table or desk is even better
    • if there is no desk available, crouch against an inner wall
  • avoid windows, mirrors, wall hangings, or furniture that falls over
• If outside
  • move to safe structure like a play ground
    • avoid vehicles, power lines, trees, and most importantly, buildings (especially unstable ones)
  • pack emergency kit in case earthquake, eliminates possibilities of getting food, water, and first aid
  • have a meeting with your family about emergencies

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